Cleaned up app generator test
Using activerecord-jdbcsqlite3-adapter

PluginGeneratorTest needs to have
activerecord-jdbcsqlite3-adapter to pass under JRuby
Merge pull request #13010 from arunagw/cleanedup-generator-test

Cleaned up app generator test
Merge pull request #13011 from arunagw/jruby-fixes

Using activerecord-jdbcsqlite3-adapter
Helper should be a module in Rails guides [ci skip]
Merge pull request #13012 from harrigan/master

Helper should be a module in Rails guides [ci skip]